Buggy code:
private ( byte [ ] source ) { } public static String encodeBytes ( byte [ ] source , int off , int len ) { } public static byte [ ] encodeBytesToBytes ( byte [ ] source , int off , int len ) { } } public static class HttpRequestException extends RuntimeException { private static final long serialVersionUID = - 1170466989781746231L ; protected HttpRequestException ( final IOException cause ) { } @ Override public IOException getCause ( ) { } } protected static abstract class Operation < V > implements Callable < V > { protected abstract V run ( ) throws HttpRequest . HttpRequestException , IOException { } protected abstract void done ( ) throws IOException { } public V call ( ) throws HttpRequest . HttpRequestException { } } protected static abstract class CloseOperation < V > extends HttpRequest . Operation < V > { private final Closeable closeable ; private final boolean ignoreCloseExceptions ; protected CloseOperation ( final Closeable closeable , final boolean ignoreCloseExceptions ) { } @ Override protected void done ( ) throws IOException { } } protected static abstract class FlushOperation < V > extends HttpRequest . Operation < V > { private final Flushable flushable ; protected FlushOperation ( final Flushable flushable ) { } @ Override protected void done ( ) throws IOException { } } public static class RequestOutputStream extends BufferedOutputStream { private final CharsetEncoder encoder ; public RequestOutputStream ( final OutputStream stream , final String charset , final int bufferSize ) { } public HttpRequest . RequestOutputStream write ( final String value ) throws IOException { } } public static String encode ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static String append ( final CharSequence url , final Map < ? , ? > params ) { } public static String append ( final CharSequence url , final Object ... params ) { } public static HttpRequest get ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static HttpRequest get ( final URL url ) throws HttpRequest . HttpRequestException { } public static HttpRequest get ( final CharSequence baseUrl , final Map < ? , ? > params , final boolean encode ) { } public static HttpRequest get ( final CharSequence baseUrl , final boolean encode , final Object ... params ) { } public static HttpRequest post ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static HttpRequest post ( final URL url ) throws HttpRequest . HttpRequestException { } public static HttpRequest post ( final CharSequence baseUrl , final Map < ? , ? > params , final boolean encode ) { } public static HttpRequest post ( final CharSequence baseUrl , final boolean encode , final Object ... params ) { } public static HttpRequest put ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static HttpRequest put ( final URL url ) throws HttpRequest . HttpRequestException { } public static HttpRequest put ( final CharSequence baseUrl , final Map < ? , ? > params , final boolean encode ) { } public static HttpRequest put ( final CharSequence baseUrl , final boolean encode , final Object ... params ) { } public static HttpRequest delete ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static HttpRequest delete ( final URL url ) throws HttpRequest . HttpRequestException { } public static HttpRequest delete ( final CharSequence baseUrl , final Map < ? , ? > params , final boolean encode ) { } public static HttpRequest delete ( final CharSequence baseUrl , final boolean encode , final Object ... params ) { } public static HttpRequest head ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static HttpRequest head ( final URL url ) throws HttpRequest . HttpRequestException { } public static HttpRequest head ( final CharSequence baseUrl , final Map < ? , ? > params , final boolean encode ) { } public static HttpRequest head ( final CharSequence baseUrl , final boolean encode , final Object ... params ) { } public static HttpRequest options ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static HttpRequest options ( final URL url ) throws HttpRequest . HttpRequestException { } public static HttpRequest trace ( final CharSequence url ) throws HttpRequest . HttpRequestException { } public static HttpRequest trace ( final URL url ) throws HttpRequest . HttpRequestException { } public static void keepAlive ( final boolean keepAlive ) { } public static void proxyHost ( final String host ) { } public static void proxyPort ( final int port ) { } public static void nonProxyHosts ( final String ... hosts ) { } private static final String setProperty ( final String name , final String value ) { } private final HttpURLConnection connection ; private HttpRequest . RequestOutputStream output ; private boolean multipart ; private boolean form ; private boolean ignoreCloseExceptions = true ; private boolean uncompress = false ; private int bufferSize = 8192 ; public HttpRequest ( final CharSequence url , final String method ) throws HttpRequest . HttpRequestException { } public HttpRequest ( final URL url , final String method ) throws HttpRequest . HttpRequestException { } @ Override public String toString ( ) { } public HttpURLConnection getConnection ( ) { } public HttpRequest ignoreCloseExceptions ( final boolean ignore ) { } public boolean ignoreCloseExceptions ( ) { } public int code ( ) throws HttpRequest . HttpRequestException { } public HttpRequest code ( final AtomicInteger output ) throws HttpRequest . HttpRequestException { } public boolean ok ( ) throws HttpRequest . HttpRequestException { } public boolean created ( ) throws HttpRequest . HttpRequestException { } public boolean serverError ( ) throws HttpRequest . HttpRequestException { } public boolean badRequest ( ) throws HttpRequest . HttpRequestException { } public boolean notFound ( ) throws HttpRequest . HttpRequestException { } public boolean notModified ( ) throws HttpRequest . HttpRequestException { } public String message ( ) throws HttpRequest . HttpRequestException { } public HttpRequest disconnect ( ) { } public HttpRequest chunk ( final int size ) { } public HttpRequest bufferSize ( final int size ) { } public int bufferSize ( ) { } public HttpRequest uncompress ( final boolean uncompress ) { } protected ByteArrayOutputStream byteStream ( ) { } public String body ( final String charset ) throws HttpRequest . HttpRequestException { } public String body ( ) throws HttpRequest . HttpRequestException { <START_BUG> return body ( charset ( ) ) ; <END_BUG>

Fix:
return isBodyEmpty ( ) ? "" : body ( charset ( ) ) ;